I removed my solid original window yesterday. Good rubber and has the chrome trim around the back window. I used two really large screwdrivers and one smaller one, all flat tip. Started on driver's side inside about halfway down. One large screwdriver between rubber and metal of cab of truck. Two inches up, second screwdriver between rubber and metal of cab of truck. Third screwdriver used to push the rubber under the metal of cab of truck between the first two screwdrivers. I worked upwards and all the way to halfway down the passenger side. As I went, I periodically applied some pressure to see how loose the glass was getting to make sure it wouldn't fall into the bed of the truck. Truth be told, it didn't get loose, but there was an inch gap from the top of the metal of the cab and the window which is still in the rubber. I got into the back of the truck, tilted a little bit, but still felt snug. Pulled slightly upward and out she came. No damage to original window and rubber unscathed. Wrapped up rubber with chrome strip and window in bubble wrap and now to decide to store or sell it.
I finally installed the Slider window using 1/4 inch cord from Home Depot. Installed new gasket (Dennis Carpenter $75 Part #D3TZ-1042084-A with great fit and looks like OEM) on the slider and let sit for half a day. It was a bear to get it on the slider just right. Then used liquid dish soap and lubed the inner portion of the new gasket. Guided bottom of window into the metal cab opening and had wife hold and apply light pressure as I pulled the window into the opening using the cord, (Sometimes called the string trick and the link is Installing Back Glass fordmuscle.com
). Wiped off gasket and it looks great and worked like a charm. My suggestion for both of these is patience and more patience. Glass shop wanted a bundle to remove and install since original 1973 glass and they didn't want the responsibility. All for the $2.50 in cord and a 1/4 cup of dish soap. Not a bad deal! This will work for slider window or solid window installation!