I did it the same way. New to me 2009 Liberty Limited came with a fresh oil change from Jeep dealer where I purchased it from. Keep seeing a small oil leak. Took off the grill and headlight, reached in and found the filter was loose by at least 1/2 turn! This by a Jeep dealer. Tightened it tight by hand and now no more oil leak. I don’t reach under cars anymore. I even change oil through the dipstick tube with a vacuum pump. Never even get dirty.Yes, that is the way I did it on my 08. Remove front grille and driver's side headlight. The big issue is getting the front grille off. You have to pull on it to where you think you will break it. But you don't. It just twangs off.
There are a couple videos out there on it. There is also one video that shows putting a screw driver down on the grille near the bottom of the headlight, and pulling a tab back, which releases the grille.
I just pulled mine til I was sure it would break. But it didn't.
Next time I'll try the screw driver but that may scratch the front.
Use synthetic oil. No sludge.Mine was very loose as well, and probably leaking at least a little.
The problem I see with the pump idea is that you are not going to get the dregs, the lowest part of the oil where the sludge might form or lay. The pump might only suck liquid, and the sludge is more of a paste, an ooze, which will ooze out the bottom, but not be sucked up by the pump.