yep chain tugs are easy to fit, put the wheel into your frame and before you put the axel bolts on put the chain tugs in and make sure the end bit that u can screw fits on the end of the frame, leave them lose thought, do this on both sides, pull the wheel back as far as possible without force, tighten the axel bolts. once done this tighten the screw on the chain tugs evenly untill it fits nicely on your frame. tighten them bit by bit evenly then the chain will get tighter.
sorry for the long writing that may be a bit confusing but its really simple to put them on.
now if its tight enough, when you push the cranks forwards there should be very little slack in the chain, if to tight the rear wheel will be hard to roll back.