I just noted this character from my font is displayed incorrectly (3) so I am attempting to correct it myself, but I do not know how to do it. I presume this is a simple task.
The software I found is FontForge. If there is another alternative that better suits these purposes, it is much welcomed to mention in your answer.
So I am attempting to copy and paste the right section of the character (5) to merge with the character (4).
But I do not know how to merge the two altogether (1), or if this practice is not recommended.
Correct. Glyphs runs exclusively on Mac. This is not a FontForge forum.
In my case, I was also somewhat desperately running a macOS virtual machine on my poor Windows laptop to use Glyphs for two years, but then finally made the switch to Mac. Can only recommend.
This is not my font file. Are you get paid for this modification? It is just one modification. I believe it takes a professional less than one minute to complete.
It is to copy the squared portion of photo 5 to the right of photo 4, to make it become photo 1, which looks alike of photo 2. Photo 3 is the incorrect character in the .ttf font file.