Wr902ac v3 8mb to 16mb storage

Hi Everyone,
Sorry for my bad english i think you are all understanding my topic ,
Im not a developer, but i want to make my device 8mb flash to 16mb because inot have enough memory for installing more packages means ftp server samba server extra features in my router so i come here for solutions, I hope all make me helpful. I have Ch341a programmer and i backup dump file from orginal firmware and i change ic 25q128jvsiq ic than i flash openwrt firmware on tfttp server i will done' all is fine but storage till 8mb not 16mb show so will research 1weak in openwrt forum i not get any fine done' solution. So i hope to anyone guide me to done' my dream anyone's guide me how it will done' i will do what you all say give me any commands to program firmware i will do in Linux terminal how to cut bootloader and art file and how to build firmware i will do anything you say i have only ch341a programmer and 16mb ic soldring kit and laptop Ubuntu Linux terminal, so guide me to make it more storage my device tplink wr902ac v3 .

how about doing https://openwrt.org/docs/guide-user/additional-software/extroot_configuration ?

on topic:

I will do this all but not work my device wr902ac v3

what all ?

what not work ?

I will try this my device but not work

Can tel me how to cut 8mb firmware, Bootloader And ART partition in Terminal Command ?

what do you mean by cut ?

i mean orginal 8mb firmware file how to take or Cut bootloader and art partition files in Linux terminal for orginal firmware , bootloader and art partition files

if you can still boot it, you can cat /dev/mtd?? > file
ART partition doesn't usually ship with the firmware.

But my wifi show signal but not working in openwrt firmware so i want to orginal firmwarebacup bootloader and art file to create new firmware openwart but i dont no how it take backup in Linux terminal.

dd if=wr902acv3.bin of=bootloader.bin bs=1 skip=0 count=131072

dd if=wr902acv3.bin of=art.bin bs=1 skip=4128768 count=65536
Is this correct? For 8mb firmware

the syntax looks good, if the values are correct, I have no idea.

you could try to binwalk it, too.