Here's a text version if you need it:
1. Make your variant with five attachments.
2. go to create a class
3. Add Afterburner as your perk 1, fast hands as perk 2, overkill in the second slot of wildcards and tactician in slot 1 of wildcards.
4. Go to primary weapons and add any weapon (NOT THE VARIANT).
5. Press triangle on the weapon and add the clan tag option to it.
6. Press X on the primary weapon and choose your 5 attachment variant.
7. It should say you need to replace some items.
8. On the replacement items screen, press X and O at the same time.
9. You should be back to the screen with all your custom classes.
10. Go back to the glitched class and remove Overkill and tactican. (KEEP THE OTHER WILDCARD)
11. Add any perks you want and you've finished!
And for anyone wondering, yes it does work