Yes, simply return to the meet entry page and select the meet and swimmer you wish to change.  

It will repopulate with your current entry selections.  Make any changes you like and hit submit.  To remove an event change the selection back to the default <select> item.

If the deadline for the meet has passed the entry form may not be available, and you may need to email or call the competition secretary email compsecncsc@gmail.com.