Vicky,
Yes you can and the good news is that you don't have to be Visa Exempt to apply. The same rule of applying within 90 days will apply. If you decide to go FPg you will need to go with these documents:
1 or 2 as above (safer to have both); and
a- Original passport
b- Current valid SP
c- Credit card/debit card loaded with $255
d- Student ID
Remember that: A PGWP is an open work permit (OWP) and therefore, it allows the holder to work for any employer, in any location, and occupation of choice. Well, apart from sex trade and strip clubs.
Be at the border office between 6am and 10am for quick and easier service. When you arrive tell the receptionist/CBSA Officer that you want to apply for a PGWP and s/he will tell you what to do next. The border officer might ask you a few simple questions such as, "what was the duration of your program?", "Did you study full-time?," etc.
Don't forget that you do not need a job offer to apply for a PGWP. If the officer asks for a letter of employment, politely let them know that you do not need one to apply for a PGWP.
After the PGWP has been printed and shown to you, make sure to check for the following on your WP before you leave the border office;
Employer: UNKNOWN
Employment Location: ANY or UNKNOWN
Occupation: UNKNOWN
If it looks different from the above, politely talk to the CBSA officer to change it. Do not assume that they all know the rules of PGWPs.
Cheers!