You need to be competent with the Dremel, or ideally air tools.
It's best to have a spare crap Vaux head to experiment a bit first.
It's very easy to wound the head irreperably, or even knock it dead.
Also having a flow-bench helps a lot, and that's specialised equipment.
If you wanna play it safe give it to someone who's done it many times before, on the same XE head, like Blydenstein. Apart from the costs of the job and getting the head in and out, it's one of the best mods for n/a cars.