It's a very doable job, provided you have some basic stuff...good set of sockets, preferably 1/2" drive, a good floor jack (2T or better) and a good solid floor to work on, some HD jackstands and some blocking, flare nut wrenches for the clutch line fittings, and a tranny jack (not essential, but makes the job a whole lot easier). A basic step thru goes somewhat like this:
1. Jack up vehicle in front as high as safely possible and support with jackstands at the LCA frame end area. Block as necessary for safety.
2. Disco driveshafts, TC linkage, speedo cable, and vac connector on TC (if applicable), put trans in N, and remove shifter from top of trans. Disco TPS wire from harness, seperate the clutch line, and disco any other electrical connectors from trans to wire harness. Loosen the TC vent line from where it's attached up in the engine bay.
3. Support trans/TC with floor jack, or install the tranny jack at this point and chain it up, and remove the crossmember *note--index the Xmember to the framerail so you install it the same way...it's not symmetrical (even tho it looks like it is)
4. Slowly lower the trans via the jack to lower the driveline. Make sure the fan blades do not have any issues with the radiator.
5. Unbolt the TC and remove, then remove all bellhousing bolts/nuts. There are 2 at the top of the housing that are a PITA to get to unless you use some extensions and a wobbly. You don't have to remove the starter on a 2.5 to pull the trans, so leave it be unless you need to pull it otherwise.
6. Pull trans backward to remove...you may have to wiggle it, or rock it up and down while pulling rearward to get the input shaft clear of the clutch housing. BE VERY CAREFUL at this point if not using a tranny jack, as it only needs to come back about 2.5" or so until it's freed and will fall straight down, compliments of gravity
7. Just like a Haynes or Chilton's manual says...installation is the reverse of removal.
You really should take the time and $$ at this point to replace the clutch components, as well as the slave/throwout, since you have it all apart. Also, get the flywheel machined and replace the pilot bearing, and consider replacing the TPS while everything's out and easy to work on. You could just throw the new trans in and bolt all the old stuff back in again and be fine, but you'll never have a better chance to do it than when it's all out.
HTH,
Jeff