Transfer RB database to external HD

HI,

My internale SSD 250GB is gettig pretty full! Time to switch to an external HD.

Question: How can I transfer my RB library to an external HD and then delete the collection on my internal HD? This way I can only use RB with the external HD connected, of course, but I will have room on my SSD for other stuff.

Will the back up function do the trick? Since i'm going to clear my internal HD, RB will lose the path to the individual tracks.

Is there a negative side on using an external HD?

Thanks!