Yes you can. No i wouldn't.
I would be like doing Brain Surgery, while moving down the hospital hall on a Gurney.
Two specific risks are entailed when making 'structural' changes to your server hosted database.
When you click OK to commit your changes back to the database, entire tables will be locked against users editing data in these tables. If this "lock" should take place in the middle of a script executing to modify data in that table, the results can be pretty messy.
Should there be a network "glitch" when committing your changes back, your database file could be damaged. And File damage is not always immediately obvious. Sometimes the problem is not discovered for many days...