All those oil tanks are poor quality, so I have had to replace and weld all of mine more than once. Even new tanks have cracked in less than 2 years so I welded them. I use my hot air solder rework station ($60) to heat HDPE 1/8" welding "rod", but I like the inventiveness of lighting HDPE tubing strips (cool). I hope the burning doesn't change the plastic much.
I access the oil line connection to the oil metering "pump" through the hole where the glove box is installed. A long arm is helpful along with the ability to feel and work "in the blind". I clamp the hose, then remove the oetiker clamp and pull the whole tank/hose assembly out to the front. You can fairly easily maneuver it past fuel lines etc.. If you disconnect the oil fill tube at the top then a full oil tank can be removed without loss. Obviously it is easy to then check or replace the oil filter. I also install a plastic quick-connect (used for fuel lines) just downstream of the filter, so the tank is easier to remove/install next time. The hard part is reinstalling the oetiker clamp at the oil metering valve, while working at arms length, through the glove box hole, in the blind.
I have stopped replacing oil filters and just check them and gently blow out if needed. Looking through the filter like a telescope you can see it is only a fine screen, so it is high flow and not easily clogged.
If you would rather, you can remove the tuned pipe and have easier access from the back side. The tank still needs to come out forward. The pipe can come out as one piece without splitting it in two, but I thought this method was more of a pain, although it then is pretty easy access.