Have now replaced complete throttle body (for the second time) and looking to overhaul defective one with repaired/new injectors (presumably by splitting throttle body) and new TPS - is it simply a question of bolting on repaired/new components and setting up TPS or does the whole throttle body need to be set up and recalibrated to the new components?

What happened to the last two? They should not fail often, if ever?

First one replaced under warranty in the early days due to indicated faulty TPS and second one replaced after circa 65k miles with fault codes for TPS and both fuel injectors.

You don't need to split the throttle bodies to get the injectors out. They just pop out with some care. Seton Tuning will clean, fit new seals and filter on them and flow test for £18 each. TPS is around £80.

HM Racing also.

Will try removing injectors without splitting TB but had seen an ADVRider thread that concluded this is the only way.

But is it just replace, plug and play?