As I know nothing of the PVS-4 and its reticles can this be done and are the part(s) available to accomplish this.
Please let me know.

Thanks

Easy to do if you cans find the reticle cell.

Stano sells them on eBay from time to time.

Switching the reticle is extremely easy.  Unscrew the cap on the front of the lens.  Then unscrew the reticle illuminator (small bulb).  Then the reticle unit pulls right out.  It is indexed by a pin and groove system, so pull it straight out, do not twist it.

Now, the hard part will be finding a mil-dot reticle.  The M16 & M14 reticles are easy to find and on Ebay all day long.  I believe the one you are looking for is an observer's reticle.  It is a cross hair reticle made up of mil-dots.  I have seen pictures of them, but have not seen one for sale in the last 3 or 4 years.  You are doing to have to keep an eye pealed on Ebay as well as ask the various vendors.  As mentioned above, you can ask the various NV companies to see if they have one for sale.

As mentioned finding your reticle is 99.9% of the issue. A monkey can install it.