There are many different options here:
Just adding coma to the search bar for replacement and use Trimto get rid of spaces:
s1 = Trim(Replace(mystring, "site,", ""))
, ( "1" - , - )
s1 = Trim(Replace(mystring, "site,", "",1,1))
/ , , , ...
TempStart = Left(mystring, InStr(1, mystring, "site") + Len(mystring) + 1)
TempEnd = Replace(mystring, TempStart, "")
TempStart = Replace(TempStart, "site", "")
mystring = CStr(TempStart & TempEnd)