http://www.rsbible.co.uk/

It tells you on there just to drill a hole-

"The Fiesta RS also benefits from having the hole drilled in the block, to allow for the CPS. Rumour has it that late 'H' plate S2's also came with this block, so this could be used. The other option is to drill the hole yourself, which would not be overly difficult, just ensure that you get it in the right place"

Feelin Confident?