Do you have to remove the existing adhesive off the blind and tube before putting on new tape? If yes, what's the best way to remove the existing adhesive?
At this stage we do not sell the tape but if you try your local hardware store they may have it . You can also tape the fabic on using masking tape . This will work as the extra fabric on the roll will hold the tape in place .
If I can't get the roll out of the brackets and dont want to screw off a bracket, is it possible to change the fabric while the roll is still on the wall?
Yes I have attached fabric while the blind was in place Just make sure it is on straight otherwise the blind will roll to one side , this is called running. There is a video on here that will show you how to fix blind running If it is a larger blind you may need someone to help you .