..i just put the jet, threads up, on a hotplate....
..get the element good and red...
..touch the solder to the inside of the jet..cpl times...
..lift it off the plate with a pair of insulated needle nose...
..douse it with a lil water....
..sometimes i tap the jet on the element to assure the solder has went thru..
..some solder primer assists, but isn't a requirement...