3D design modification (split into 2-3 parts for 3d printing)

I have a .igs design of a 10/22 rifle stock it's a model of the original factory stock i need the model split into 3 pieces for 3d printing in addition to splitting into 3 pieces each 3 pieces need to be slotted so that when 3d printed they can be fitted together and glued properly should be a fairly quick and easy job for some one proficient in fusion 360 slotting example

https://www.thingiverse.com/thing:2893553 is a example of a aftermarket stock how i want this model split and slotted will be similar to the above thingiverse model

I will need the updated .igs file as well please provide exported .stl files as well