Slic3r is an open source 3D printing software supported by a number of developers. Documentation for Slic3r can be found at the following link: https://slic3r.org/. Slic3r is versatile, popular, and free to use.
Go to View > Printer Settings
Click on Bed Shape and enter in values as seen below:
Click on Extruder 1 in the left-hand pane
Set Nozzle Diameter. For SAAM, the default nozzle diameter is 0.4mm. For SAAM HT the default nozzle diameter is 0.6mm.