I was told by my mechanic that I have very little time left on my idle arms on my van. The cost in replacing both of them would be $320. Is this something I could do myself.

What kind of tools would I need for the job. I can get new idle arms for about $100 each. Is it a possibility of getting them from the wreckers or should I just stick with buying new ones.

You should get a second opinion.

The arms may not be bad or even sufficiently worn. A certain amount of deflection is normal per GM (Read my profile). And some of the lash can be tightened out of them. I'd try that first: the big nut on the lower end of the pivot is the pre-load nut. (Fairly difficult to turn, clockwise to tighten)

If, however, the idler arms haven't been lubed properly, they may indeed need replacement.

Special tools? You may already have a large enough persuader (hammer) but you'll also need a way to separate the arms from the center link. This is usually done with a special "fork" for that purpose. Weigh the price of this tool against the price of paying someone to do the work. Bear in mind you may never use that "fork" again.

And, yes, if they need replaced I'd get new ones.

A quick call to Auto Zone provided a price of $38 for left side, and $46 for the right. You should be able to handle this job yourself, with perhaps a bit of help from a mechanically inclined friend. Do you realize how much beer you could buy with the money saved?