I have read that it is best to try and remove old caulk before recaulking and restaining cedar trim on a house. Is there a tool to make removal easier? If the old caulk is sound and not falling off, can you caulk over it? Any thoughts from the painting pros out there? Thanks

The best tools is a utility knife to slice the old caulk bead on both sides. We use a painters 5 in one tool and I think its now called a 7 or 8 in one because it opens a bottle.
Part of the tool is curved to scrape paint off the roller when done. It has a flat blade in front of that and at the end of that it has a sharp point to get in and behind old caulk and pop it out, on the side has a can opener

Another good tool has a triangle blade/scraper that works well tol.

8 8 in 1 putty knife(HW048b) - Handyway Enterprise Enterprise Corp. Limited(HW048b) - Handyway Enterprise Enterprise Corp. Limited) (http://www.allproducts.com/manufacture97/handyway/product5.html)

Bahco / Sandvik Triangle Scraper Blades (http://www.jamestowndistributors.com/userportal/show_product.do?pid=54187&familyName=Bahco+%2F+Sandvik+Triangle+Scraper+Blad es)

Of the old curved paint scraper is still used