advice on seals on 2l-t mechanical injector pump

[Ryanjury]

I seem to have no end of issues with my surf.. The latest issue is the injector pump is leaking.. it appears to be leaking around the side that is labelled thermal wax. I have read lots online about doing the seals with the pump still on the engine. But then lots of people saying not to touch it. Has anyone done the seals on one of these? Can anyone offer some advice..

The pump is leaking only when cold.