Recently found these handy little tools from Site Sponsor Coffee Parts making Group Seal removal easy with less chance of accidental damage -

Finally got around to replacing the existing 8.5mm rubber group seal with the correct size 8mm Cafelat Silicon seal using these tools. The near semi-circular shaped tool was the one I used. Fuss free and easy job so decided to share the link with a recommendation that they are worth having, especially if including other parts in your order so you don't pay the postage just for the tools.

Currently Coffee Parts have 10% discount - Coffee Parts 2018 Discount code