Can you undo a multi class selection?

One of my players selected multi class but is unable to remove it and go back. Is there any easy way to remove that option or do I need to start over with the character sheet?

Hi Mechant,  Which character sheet are you using? If you don't know the name please supply a screenshot.

I hope this helps, if not, please let me know.

For future reference, that's the D&D 5e 2014 by Roll20 sheet (A mouthful, for sure). You can manually edit all fields relevant to multiclassing on this sheet - the settings for multiclassing are on the sheet options tab, accessed from the gear button in the corner. There, you'll find a "multi-class options" panel: You can uncheck those multiclass options, and then just clean up any features and such that the character would have gotten from that second class.

What Tuo said. :D

Perfect!  Thank you for the correct name of the character sheet and the info to change it!  I was trying the gear icon by the name to no avail.   Unchecking worked so thank you again to you both. :)