there are a few ways
one that is VERY SIMPLE but has issues of having strait lines for latitude instead of curves
-- NOT a good choice for your project
it is the built in program in NetPPM ( likely installed on most linux os's ) but will run in Windows" ppmglobe "
a 8 gore map conversion from Simple Cylindrical
Code:
ppmglobe 8 lines10.ppm > 8gor.ppm
HOWEVER that has issues
a better option is to use a GIS program like Qgis ( it is under the GPL public license -- FREE )
depending on the number of gores you need ( using 8 for this also )
first cut the Simple Cylindrical map into 8 equal vertical strips
remap each them into TransverseMercator with the longitude center of ZERO and range
MinimumLatitude = -90.0
MaximumLatitude = 90.0
MinimumLongitude = -22.5
MaximumLongitude = 22.5
and do this for all 8 gores
then you have to print each out
-- THIS IS NOT!!!! adding extra for overlap !!!! you will need to calculate that , if needed