If you have a BASIC 2.0 PET handy (I wouldn't
recommend this with an
original PET) and a 3040 or 4040 disk drive, you could load the
program on the PET, save it to diskette, then move the diskette to a
1541 and pull the program in with an X1541 cable. There were also
programs back in the day to migrate tape programs right to disk. This
would be a good path if you had a whole PET setup.
Alternatively you could connect the PET disk drive to a PC (or other
computer) with a GPIB/IEEE-488 interface. The command set for the
Commodore drives is well-documented, it shouldn't be hard to write a
program to read the file off the disk. I know somebody who saves/loads
programes from his Tekky 4052 on a PET disk drive...
Of course 1541's are probably easier for most people to find than machine
with GPIB ports...
-tony