Need help making a custom firmware for tplink-wr940n v6 to free upsome space

I need to install sqm qos but there is not enough space left. I have not installed any other package since firmware installation. Need to remove ipv6 files to free up some KBs. I dont have any linux OS. Can somebody build a custom firmware for me tysm.
I m a complete noob at this sorry.

There's an online builder here: Online ImageBuilder and Upgrade Server

You can remove some of the packages that are listed in the drop down box. If you want to remove more you add them with a minus sign in front, for instance -opkg. See this page:

If you want to do more, like adding zram swap or increasing the block size to get better compression, you can use this guide:

I m stuck at "u are in build queue position".