Advice on PDF cracking

I have tried to get Hashcat to crack a PDF.

The type is: 10500 | PDF 1.4 - 1.6 (Acrobat 5 - 8)   | Documents

I am not asking anyone to crack it but could someone supply the command line i need run and use AMD device 1

I have tried but i am lost with all these switches.

thanks

ac427