You could make the opening larger.
For valuable garments or delicate fabrics, consider getting professional repair advice rather than experimenting with further cutting.
Common Seam Ripper Mistakes to Avoid
A seam ripper is simple to use, but a few habits can make it much safer and more effective.
Don’t Rush
This is probably the biggest one.
When you’ve sewn an entire seam incorrectly, it’s tempting to tear it out as quickly as possible.
Unfortunately, rushing is when accidental fabric cuts are most likely to happen.
Slow down.
Your future self will thank you.
Don’t Pull Hard on the Thread
If a thread won’t come loose, don’t force it.
There’s probably another stitch holding it in place.