When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
You need to completely remove all the old glue and then use a good quality double sided tape like 3m or such like.
All the old black does come off but it takes a while. I soaked it in autoglym tar remover and then picked it off.
Or, you could just ring ICP and order a new one for about £15.