The shackle install is very easy -

1. Jack up the rear and set the frame on jack stands.
2. Remove the 2 nuts holding the shackle bolts.
3. Slide the old shackle out (this is a little tricky on the drivers side due to the exahust, but it will come off)
4. Connect the new longer shackles to the upper mounts - tighten the nut/bolt finger tight.
5. Use the sisor jack to help align the leaf spring with the shackle and install the lower nut/bolt.
6. Tighten all bolts and set the X back on the ground.

The T-bar tweak isnt much harder -
1. Lift the X in the front - set the frame on stands.
2. Loosen the lock nut (this is the top 19mm nut of the pair on the top side of the T-bar adjuster and you will likely need 2 19mm wrenches although a 3/4" will work in a bind)
3. Turn the adjuster clockwise to raise your X (I found that each full rotation lifted my X not quite 1/4" so 5-6 full rotations would be a good starting point)
4. Lower the X off the stands and measure the distance between the upper control arm and the bump stop (look and you will see what I am talking about.) This distance should be somewhere between 1/2 and 3/4" (the less space to the stop = more lift)
5. measure both sides of your X and adjust as desired making sure to keep the height even on each side.
6. Re-tighten the lock nuts on the top of the adjusters.
7. Get the front end aligned and enjoy.

Don't be afraid of the T-bar adjustment - it is something you will need to learn. Even an untouched X will start to sag in the front and require adjustment now and then as the T-bars lose strength.
Remember nothing is free - in gaining front lift with a PML, you are giving up droop. That being said a PML is a great cheap way to firm up the feeling of the front end change the appearance of your X.