I have had some painter's tape on the side windows around my front door which I have had trouble getting off because it has been there a while. I tried taking it off one day but got frustrated and I haven't touched it since. Today was one of those days where I was determined to do something about it so I did some research on the internet and this is how I removed it:
I took some olive oil and rubbed it all over the tape and tape residue. I let that sit for about 10 minutes and then I took a chisel and scraped off the tape which came off rather easily. Then I made a paste out of baking soda, Goo Gone, and dish soap. I rubbed this all over the tape residue and I let that sit for about 10 minutes. Then I took a cloth and scrubbed off the residue. I had to use the chisel again in some places. I finished it up by cleaning the entire glass with window cleaner. Now my window looks great and I feel much better.