Electronic trunk will not open at all

I have a problem. My electronic trunk on my Plymouth Voyager 2000 will not open either with the remote or the key. I have been advised to remove the interior panel and attempt to fix it this way, however, I do not know how to do this. Is there a special tool that I need? Where do I get it? Where do I begin to remove this panel?
Also, My driver side window has been disconnected, also electronic, because it gets stuck in the down position.
Thi final problem I am having right now is that my air conditioner is not holding a charge. How much money am I looking at spending to make this care safe for my son and grandson who both have heart and respiratory conditions? and ar these repairs something I cna do myself?

If your trunk won't open with the key or remote, sounds like a problem with the latch assembly on the trunk door itself. If the window gets stuck in the down position, you have a bad window switch, simple to replace and cheap, if you go to a junkyard. Your A/C, depends on where the leak is, if you have one. A/C work can be pricey, even if you do it yourself.