below you can find instructions how to install FourierTrigSeries module. It is written for Maple 10 but should work also for other versions. The module itself was tested on versions 8, 9, 10, 11. It wasn't tested on Maple 12 but I hope it should work.
Suppose the Maple is installed in "c:\Program Files\Maple 10" and FourierTrigSeries module files are stored in "c:\Program Files\Maple 10\fouriertrigseries" (the directory path can contain space blank characters).
1. Close all opened Maple sessions.
2. Create a plaintext file "maple.ini" in "c:\Program Files\Maple 10\Users" with following content:
libname:=libname, "c:/Program Files/Maple 10/fouriertrigseries":
This tells Maple to search modules also in the directory where our new module is stored.
Use forward slashes instead of backslashes. I recommend to use double quotes to enclose the directory path.
3. Start Maple session and try to load the module with command " with(FourierTrigSeries); ". The module name is case sensitive, you have to use exactly this form. The module name used inside "with" command has no relation to the directory path where the files are stored.