Stripped thread on cylinder head for spark plug (no. 4)

Hi all,
Managed to strip one of the spark plug thread's on the cylinder head. Cross threaded I think. Looks like I need to try cutting 4 groves into the spark plug, add grease (place a paper towel into the hole and start creating) and then try threading a new hole. Messy job... any ideas or hacks that don't involve removing the head?
Thanks,
Nicks

A thread forming tool, not a tap, would be worth a try if there is still enough metal left.  These tools work by reverse threading.  
www.amazon.com/Powerbuilt-640811-Back-Ta...epair/dp/B0014FGVVW/

Failing that, you will need to install an insert.  Timesert is ideal but the kits are expensive.  You can use grease on the tap and/or drill to catch chips.  A tube on the end of a vacuum can be used too to suck up swarf that's formed too.  Realize also that a few small aluminum chips won't typically hurt the engine; they will burn up and pass out the exhaust.

Thanks for the info and tips

If you need to make new threads I think time sert is the best solution...?

eshop.wurth.co.uk/Product-categories/Spa...3108.cgid/en/GB/GBP/