Hi Diggydude.
I use one of these to install the frets...
https://www.ebay.com.au/itm/Guitar-M...97.m4902.l9144
You'll need to get a brass insert of the correct radius for it....
https://www.ebay.com.au/itm/Brass-gu...wAAOSwbKdcE02A
Some of them I make doubly sure by using small amount of glue.
cheers, Mark.