Shift kits are not that hard to install especially if you have a wide tool section at your finger tips to use and are mechanically incline. If you have any doubt about do it, i suggest taking it to a pro tranny shop that is well know and have them install it for you. That way there they can also make any adjustments needed to the bands and kickdown cable for you.

Whilt you are in there, install a new filter and if you ever take your vehicle to a track, maybe think about installing B&M's trick shift fluid.

 

Not sure what year car and tranny you have, but for 66' onwards there are a variety of shifter kits out there, most don't need any special tools and can be done by any backyard mechanic, if you can change brakes you can install a shifter kit!

pre 66' 727's are a different story, they use a different cable setup and I've yet to find a aftermarket shifter for them!