Got given tow bar for bug, how do I install?

I just got a old tow bar from a neighbour, but it doesn't have any bolts, just the main bit. And the ball bit.
How do I install it, and do I need any of the missing parts, or can make shift stuff be used.
That is, I don't want to search everywhere for a expensive rare part. If so, I will forget installing it.

Is this the type that slots in bewteen and bolts to the rear bumper mount plates??

On mine there are basically 2 parts, the tow bar assembly and the bolts/nuts.
You line up the towbar assembly and drill through the bumper mount plates where the bolt holes are and bolt it up
Voila.

I could get you some pics if you REALLY need them.