The repair involves drilling out the product to the next up tapping size, tapping the thread, then inserting the threaded insert to reduce down to the original tapped size - but now with a wear resistant insert.
As with all hand tools you get what you pay for - this range of thread repair kits & inserts are the best available. The thread repair kits include drill, tap, insertion tool & tang removal tool plus a good quality of inserts. Additional insert packs are available at extra cost, please enquire ?