How hard/easy is it to fit a manifold onto a MY03 sti type uk with ppp?

I am looking to change the standard to a roger clark item and just wondered what sort of time scale and how hard/easy it is to do?

Regards

 

pain on the **** m8 but well worth the outcome
took me to remove inlet swap bits and bobs and refit around 4hrs working time

 

any more help much appreciated, cant seem to find a guide anywhere.