The common rule is that once the three kings are set they have 13 moves to win.
Both Gonyaev' Shtyk
and Petrov's Triangle work but
Petrov's Triangle is easier to remember.
There are three stages:
Stage 1 - take both double lines.
1.cf4
ga7
2.eg3
ab6
3.gh2
bg1
4.ah8
gc5
5.hg1
cb4
Stage 2 - while on double line take one of tripple lines, this forces the opposing king to leave the other tripple line.
6.ge3!
be7