I need some help with regex with this test string:

Kershing_User ID/Electronic Delivery_6ZZ138429_ 3142-999999__1

I want one match to select everything except the forward slash, so this would be acceptable:

Kershing_User IDElectronic Delivery_6ZZ138429_ 3142-999999__1

Even better would be to return this with a substitution of a _.

Kershing_User ID_Electronic Delivery_6ZZ138429_ 3142-999999__1

I know how to do lookarounds and can individually match the part before and after the /, but not all in one match. Anything else I have tried has come up with two separate matches. I am using this with an application called Laserfiche, so as far as I know there is not the ability to do find & replace or to extract a group, just doing it with one match. My regrets if I don’t have the terminology correct. I am not even sure if this is possible. I tried for a while and come up with these below, but can’t get it in one match.

This does the before: .*(?=\/)

This does the after: (?<=\/).*