As far as the slant goes, that is most likely not shock related. The shocks do not do anything for ride height, that would be springs and the spring isolators. If its sagging one way or another I would look into the springs and see what's up.
If you do still want to replace the shock they are easy to remove. Under the hood there is a nut u screw off the top stud of the shock, which will release the top, and on the bottom just unbolt the 2 bolts and take out the shock. For the rear just remove the upper and lower bolts and pull them out.
I also would suggest not going with the cheapest shock u can find. Any decent mono tube will most likely give u the best ride quality, but they are not the only options. And it may be a good time to put on a 2" Bb since you would already be replacing shocks.
2001 Grand Cherokee Laredo 4.0L Patriot Blue (Named ATOM)
Interior: Pioneer DEH-P4900IB Head unit, Eclipse SE6900 6x9 Front speaker, Alpine Type-R 5 1/4 Component Rears, Alpine PDX-F4 Amp.
Exterior: IRO 3 inch Lift, 265/75-R16 General Grabber AT2's, 40' Rigid Industries SR SERIES LED Light Bar, Saguaro 3/4in Shackle mounts, Rola Roof Rack, Kolak Stillen Rotors, EBC green stuff pads, Addco Rear Sway, KOR 1.5" Wheel Spacers