Ebay has Implements & Tractors (I&T) manuals for sale for around 25 bucks give or take. I have several covering my tractors listed (FO 40-43 area for me) and still have a manual for a 4600 I used to have; don't remember the FO#. I'm having my morning coffee right now but later on today I'll go out to the shop and check through my manuals and see if I can find something to help you in solving your problem.
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Update:
FO-41 covers the 4110. Page 80 starts the hydraulic section. There are 2 filters on the line, Item 1 of figure 240 is the return line and screen...seems the screen and line are one component. Comment: Flushing that filter, with the lift cover removed (which you have done) could be accomplished with the sump drained (as you have done) and Brake Parts Cleaner in the aerosol...just flush the debris off.
Item 8, the filter element and apparently the object is held in place with a nut and flat washer on the far end of the filter....not visible in your first picture.
It appears that the pipe in your first picture just pushes up into the gear type hydraulic pump. I would assume that you remove the bolt/nut whatever, holding the tube's bracket in your first picture, to the housing and then pull the tube out of the pump subsequently working the tube up and out of the housing. Manual makes no mention of having to remove any other components to access the filter.
Questions, ask.