GM just glues those oil tubes in.
a light coat of high temp silicone near the o-ring should do.
don't know of any "tricks" but, pulling anything out of the way first is the easiest. you shouldn't need a lift, but the vehicle on ramps would help. also, once on ramps, you could still jack up the driver's side, to pull the whell and inner skirting, to assist some clearance and able to get impacts through the wheel well area. if power steering or air conditioning is in the way, you can pull out of brackets, and tie wrap them or prop them away from the area of work WITHOUT draining fluid or freon! having the cat up in the air partially will also help getting the exhaust pipe bolts, which you should soak with penetrant before starting all your removal of other items, so it has time to work in.
also pick up some heat treated exhaust bolts and studs from auto store or dealer, in case you break them(or decide it is easier to tighten them, forcing them to break), you have them, and I'd still replace with new, so the next time (if there is one), bolts are not siezed.
hope this helps,
chris
nrt racing