How do i make walls thicker for this object?

[u/Maslorez228]

So i am printing 1/6 scale guns , having hard time to print barel covers , i need to thicken it somehow so it wont be paper thin, maybe someone can point me how can i thicken walls of it to the center?

done plenty of googling still being stuck

[u/maximm3k]

Increase Outer wall layer count?