GM Repair Problems? Ask GM Repair Expert Now.
If you look at the fittings there will be a small round plastic cover on the line side of the fitting. Slide the plastic piece off of the fitting and there will be an E clip. Use a pick to lift one side of the E clip and rotate it off of the fitting. Then the line will come out of the radiator or the oil filter houseing so you can replace the lines. When you put it back together use a new E clip on the fittings.
There may be a bracket the lines are clamped to, but that should not be a problem to unbolt the lines from. If you need a diagram or two for the E clip or the lines please let me know.
You should not have to lift the engine, you do have to rotate the lines so the bends will come out around the mounts. Take your time and do not get forceful with them. Are you trying to get them to come out the back or out towards the radiator?
It is best to go from the engine towards the radiator.