Delete one file within folder

There are a number of posts on here about this, i included 2 links below. the 1st methode is what I used however the 2nd methode looks to be easier however I believe you said you are using Apple and I have no idea if there is an equivlent to winscp for it

Proceede at you own risk, if you are comfortable with Unix/Linux it is very easy if not use extra caution

1st methode

2nd methode