How to Build yocto file

Hello. Could you send or explain how to build yocto for yellow mango.
As far as I understand, all the drivers for the board are contained in legato, but the drivers for wifi are already in yocto. I had installed FW R13.3 Generic to mango and now using toolchain version 02.28.03.05

You can use leaf or github

Download by Github:

Could you write the step for me how to build yocto file?

thank you,

you can see here for leaf:

you can see here for Github:

these instructions don’t work. The repo sync tries to pull files from repos that don’t exist anymore.

how about using "leaf getsrc "?