Merging amour is possible by wearing heavy armour on your C1 outfit and nothing on your c2 outfit.

Save the armour you want in outfit slot 1 and merge in Crooked Cop

Hit this with the Israel bag


You can use the chart below if you have CEO or SWAT armour on your C2:

C1 Outfit
C2 Outfit

Crew Armour

The available armours in-game can only block up to red, after that the armour will need to be merged. Use the below chart if your coloured armour is on C2: