Not quite that simple. You need to set the spring in the compressed, lock position, then install it in the car.
Check how loose the cam chain is on the tensioner side of the block. Then use a wooden paint stick, and a rubber hammer to "bump" the cam chain tensioner, and then it will release it from the locked position. Recheck how loose the cam chain is... if you were successful, there should be some spring tension on the cam chain.
The first time I did this, I didn't notice any extra tension on the cam chain, so I re-bumped it. Tested. Bumped it harder, tested. Couldn't notice any difference... so I took it out, and discovered I broke it. A screwdriver and hammer was too big of a bump. A paint stick worked on my 2nd tensioner, and I never could get the cam chain test to tell me it worked, so I drove it. It is fine.