Piece of cake! Just buy a new larger capacity SD card, Sandish class 10 preferred, then copy all files in your old card to the new card.

Hmmm, are you using a Sandisk card? Sometimes, the card brand matteres.

 hi. I have done this numerous times with no problems and on different makes of sd card. I just copy old sd card to desk top on your computer, then insert new card, format the card first, then send copy of old card on your desk top to new card........all done.
hope this helps.

Yes, that is also how I do.