Hmmmmm
Well it could be cake or it could be,,,,,,
well not quite cake. ( toast and butter ? )
Many Ford glass is bolted in with 11mm nuts. If this is the case, remove all the nuts and press out evenly, bit by bit.
To replace simply clean off all the black goo from the window and the window frame, clean and replace with new correct size "window kit". Avalible from an automotive glass shop, or some auto parts stores.
If it is not a bolt in then you will need a window knife and a good breakfast.
Cut out the glass, clean, prime, and urathane to reinstal. Do note, if you attempt to use the urathane your self, be warned this stuff WILL stain, it WILL get every where, it WILL ruine paint and it will stain your fingers for no less than a month.
Have a good time
Let me know if I can help any further.