global accessories texture editing

[ap18]

hello
im new in all the edit staff i just learnd how to export dds file to your global and i have gimp and mod tool.
im trying to make a gloal for my self from al the globals i found online(wont realse it because even the original global is not mine its for a personal use) now i want to do two things
1. i want to edit a few accessories and make them longer (like long hexpad but with other accessories)
2.i want to add a logos for some acceossries(like arm sleeves and hexpads )
i dont know how to it so i want to ask if some could help me please?
thanks any way
by the way thanks jaosming for his youtube toturials this is how i learnd to usee the mod tool
i tryid search in his channel but i didnt find something that can help me