Can you write a new frequency over the old? And then lock out if you don't want to use while scanning. It is generally real easy to overwrite a frequency on Yaesu radios.
Sorry I misread your question.
Like many Yaesu radios, it appears you can't delete a memory location from the keypad once it has been programmed. You can overwrite it with new data. You mask it so you it is not visible (see the Operating Manual page 26). You can mark it to skip during a scan, but you can't delete it. The only way that I know to delete it is by using programming software.
Can you write a new frequency over the old? And then lock out if you don't want to use while scanning. It is generally real easy to overwrite a frequency on Yaesu radios.