Undo tablespace way to large

 I have a situation where my undo tablespace has grown large and needs to be dealt with before we run out of space on the drive.  The actions I plan to take are:

Create a new undo tablespace on a different drive

Create undo tablespace UNDOTBS2 datafile 'E:\.......\.....\undotbs2.ora' size 50m autoextend on;

Then I will switch the undo tablespaces

Alter system set undo_tablespace = undotbs2;

Then I will wait for the old tablespace to stop being used

Here is where I need to ask a question

I read that I can drop the old tablespace since the new one will now be used.  Can I also drop the datafile along with it?  This is a production database and I need to reclaim that space and believe this is the correct action, but need it to be confirmed.