Info On POI's Editing

I would like to now if you can Edit poi's that were on my Tom Tom One XL Europe from new ie As it has a Listing for Petrol Station can I add to it as i find a lot of things in Central London are not Listed there either miles away or in foreign countries
Also can I delete poi's ie I have ( Ice Skating Rinks ) I don't want them but cant find them in poi's folder.
I don't want to get rid of all poi's just the one's I now I'll never use
So just to make sure you understand what I'm looking to do

I want to Add Entries to Existing POI's ----Take away Entries within Existing POI's
Thank for anyone that can help
John