If you get the revision 2 and check out and edit the data, It creates a new version.And the Version which created the revision will still be available as is.
I would suggest leave it as is, because its the old version file.
Just my opinion.
What Raghavendra proposed does work but sounds like editing a document in a Released state.
My document control policy has always been to leave it until the next REV or ECO to maintain version history integrity and keeps all the editing on the radar.
If you can edit the Released version, it will raise concerns about the integrity of your data management system. Also, if your organization submits to any regulatory agency, it could cause some very real issues and tough questions to answer.
technically, it can be done. but you have to do it completely through the back door, and there would be no history of it happening.
leave it alone - everyone has old versions/revisions somewhere with errors in them - that is often why new version/revisions were made
The answer is a qualified no. As others have noted, if you modify revision 2 you will be creating a new version which will be a higher version number (and more recent) than revision 3.
You could 'rollback' to the earlier revision, but you would lose revision 3 and need to redo...
So, as others have noted - it's best to leave it alone.