OK, first of all the syntax was sourced from here so all credit goes to the original author.
As you seem to have many variables where this will need to be applied, it is best to use a macro so that it can be called once for each applicable variable rather than having to copy and paste the syntax and swap out the variable names. The following will split the variable into a predefined number of values (choose the maximum number of possible answers, currently set at 5) and write the new variables at end of the list. C254 will become C2541, C2542, C2543, C2544, C2545.
You'll need to append this '!parse var=VAR nbval=5.' to the file for each variable you want to split, filling in the appropriate variable name and number to split where red. You'll also get errors when cases are empty, but these can be ignored.