Hello!
You can try using the "Find & Replace" feature on Auctiva--you can change the Buy it now price, duration, seller details, checkout details, etc.....it's quite a time saver!
The first thing you need to do is create a Checkout Profile that will refect the new changes you want to make to your listings (paperless.) You make the new profile by going to the Profiles tab, then click "Checkout" in the Create New Profiles window. Choose the new payment method(s) you wish to use and enter payment instructions. Name the profile something easy to remember (for future reference) like "PayPal only"--Hit Save on the bottom.
Next, you need to go change your active listings on ebay, which is easily done since you have already made your new checkout profile. Go to the "Listings" tab and click on "Saved Listings." Check the box next to the listings you need to fix and then click on "Find & Replace" on the top of the window.
Where it says "Select Field to Update" choose "checkout fields". Then you will have another drop-down menu appear and that is where you will choose the Checkout Profile you just made. After you have chosen the profile, click Continue--that will take you to a confirmation page. Click Confirm Selected Listings and you're done. Allow a little time for the change to be made on eBay's site.
Hope that helps--sure saved me a lot of time!