There is a way but no simple one: Code it.
First off a Homebrew running as a Channel needs to implement
ProcUI correctly. That alone is a challenge as ProcUI is a beast, so many HB devs just didn't care. Second a homebrew on HBL reloads itself to exit back to HBL. A Channel should reload to the Wii U menu instead. For reload control have a look at
https://wut.devkitpro.org/group__sysapp__launch.html as well as various sourcecodes (like Tiramisus) as there are also better but largely unknown reload methods.
After that many homebrews will just work. Others, like WUP Installer, will need a rewrite (if you look close you'll notice that WUP Installer HBL is a .elf file while the Channel contains a rewritten .rpx file, for example).
With that knowledge (as well as basic programming knowledge) it should take less then a year to make your first Channel. Then maybe less then three months for the next and from there on it's routine. In case you you lack basic programming experience (how do pointers work or better: How do you work with them, for example?) we might talk about years for your first Channel throuh.
//EDIT: To give you an idea about what a beast ProcUI is: I'm implementing it since 2-3 years into NUSspli, still it's not correctly implemented (but that's also extemely low priority for me as the only thing not working is sending the homebrew to background by pressing home - NUSspli is designed to exit on home press anyway).
//EDIT²: But go ask my beta testers how many months it took untill NUSspli channel was able to exit from all possible combinations (pressing B, so homebrew introduced as well as pressing Home, so ProcUI introduced as well as pressing the power key and so on)... And how many more months untill the last bugs with that where fixed...