Changing an automatic transmission driven vehicle to a manual transmission driven one can be an arduous task. The rewards to having more takeoff power and better fuel economy may be outweighed by the difficult task ahead. Only a person having mechanical skill and aptitude should even attempt this conversion. Even then, you may want to think twice before going ahead with your project. Remember, you may have to alter the vehicle far more than just removing and installing the transmission itself.
The first thing you should do is get the service manual for your ride. This will be necessary for even seasoned mechanics as the steps you will have to follow are many and the details can get confusing at times. Read through the sections having to do with engine/transmission removal and installation. This will allow you to "get to know" the drivetrain and applicable components. If you are comfortable with what you have seen so far, proceed to researching the conversion.
Researching the conversion for your particular make and model is extremely important! You have to know that what you about to attempt is even plausible or possible. Newer vehicles have many switches and solenoids, on-board computers, relays, and other gadgets that can be troublesome for this project. Make sure the transmission you intend to install fits. Your local transmission shop can be the place to find the information you seek, but their time is money so they may simply brush you off. You may have to research online, or call performance parts sales facilities to eventually find the information that you require.
Now comes the fun part! To begin your removal, you will need to begin by securing the vehicle for the task. Generally speaking, this includes parking it on a level surface, engaging the parking brake, chocking the rear wheels, and disconnecting the battery. Once you have done this, you will need to disconnect the electrical components and/or hoses that may be in the way, labeling them accordingly. This will allow you to more easily return them to their proper places.
Once you have all those pesky wires and hoses out of the way, you will need to jack the vehicle and secure it on stands. Always use jackstands to support your vehicle! Using only the jack can allow it to fall and cause injury to you, possibly even death! Besides, if your beauty falls to the floor it may destroy valuable parts and cost you money, time, and inconvenience.
From this point you will need to proceed with removing the transmission. This requires disconnecting the driveshaft(s), mount brackets, and transmission lines. Once you have uninstalled the peripheral parts of the drive assemblies, you will need to support the transmission. Now, remove the inspection cover and flex-plate to flywheel bolts. Afterward, it's time to remove the transmission-to engine mount bolts, making sure that the transmission is secure on it's supports. You're ready to lower the transmission out of its resting place! Take a breather and get yourself a drink! You may have a long way to go from here.
Once you've made sure your new manual transmission will fit properly(including pilot bearings and flywheel), you will need to install the clutch pedal assembly and all necessary components. This may include clutch master cylinder or cable and other such parts. If you have done the proper research, you will have these available to you. You may also need to alter the floorboard of the vehicle to accept the shifter.
Having installed the necessary extras, you're ready to slide the new transmission into position under the vehicle. Carefully raise it into position and slide it's pilot shaft into the pilot bearing/bushing. Making sure it's securely supported, install the transmission-to-engine mount bolts.
The next part is simple compared to the previous steps. Reinstall the mount brackets, driveshaft assemblies, wires and hoses. Don't forget to install plugs into the holes where the automatic transmission's lines connected to the radiator. If you're sure that all components are properly installed and aligned to proper specifications, lower your ride back to the floor, connect the battery. Make sure all your tools are removed from the various places you've stashed them. Check that everything works properly, ie: shifter and clutch pedal. Start your engine and go for a spin!