Just joined and already mentioned so sorry for repeating myself. I need to know how to push in the new window after repainting the oil tank? I'm a little worried about just simply trying to push it in. I would try warming the new window and it's rubber and smearing oil about it and the hole. Is this the only way?
 

This topic just came up within the past week. Maybe do a search as there are various opinions. Myself I always remove them before painting. Usually drill the center then insert wood screw and pry it out. Others have pushed in only to find baffles keeping it from coming out the fill hole. Others will chime in and then proceed at your own risk!

+1 for the drill and pull. Very simple to do.
Installing my new one was very easy after putting a light film of oil on the outer surface. Didn't take much force at all. Popped right in there.

Hello! No, I managed to push in with a long socket, found that easy. It's installing the new one I'm deliberating on?

Installing the replacement I use a plywood disc about 2 inches diameter and press that against the new window.
Using the disc will stop you pushing it in too far, which is what I did on my first attempt, lesson learnt
A little oil on the rubber will help too.
Good luck.

Thanks Schu! Yeah, tomorrows the day. Not much any other way really is there? Warm up the window rubber, bit of oil and pop in she goes Lol.

I have never removed or installed one, but have been a heavy equipment mechanic for many years, after reading of many failure of pushing it in and not being able to retrieve it from the fill hole and some members just leaving it in there, my choice would be to use the drill and use a wood screw and vise grips to remove it, opposite of the way it went in. On installation I would use PETE-RT1’s method of installation, I also read of many members having pushed it all the way through and ending up with a new oil sight glass inside the tank.