Do I have to remove all the stickers from the utensil before I am tovel it?
Stickers that a person doesn’t want to stay on the utensil and he is planning on removing them anyway, must be removed before being tovel the utensil.
Stickers that a peson doesn’t care about and wouln’t mind leaving them on the utensil indefinitely (such as on the bottom where it isn’t noticable), one should preferably remove them if it isn’t overly difficult. If it will be difficult to remove, one can leave it on.
The Shulchan Aruch (Y.D. 202:2) rules that anything stuck on which bothers a person is a chatziza, but if he doesn’t care about it then it’s not a chatzitza. However, see Rama (Y.D. 198:1) regarding tevilat nidda that one should try to remove even things that don’t bother a person. The Chochmas Adam (73:14) and Aruch Hashulchan (202:2) sound like this applies to tevilat kelim also.