Accessing inside of Door/ Installing Keyless entry

Hi, 89 Jeep Cherokee Laredo 4 door

2 part issue -

Am I supposed to have problems accessing the inner part of my car doors? When I take the door panel off there is still a metal layer blocking in the innerworkings of the door (window channel, door locks). There are openings cut in it that allow me to access some stuff but not really enough of an openings to let work. It appears I would need some specialized bits and actually take the door off the hinges to get this piece off. Is this supposed to be the case?

Also, does anyone have any experience/advice about installing remote keyless entry? How will the above issues affect this installation? thanks