Links below include original links from makers. Ask their FB, twitter, forum profile or below for others.
1. Download the PES2021 Menu Mods V3 .RAR Archive.
2. Take the “Menu” folder from your chosen menu mod & copy to your Sider “livecpk” folder.
3. Add the line cpk.root = “.\livecpk\Menu” to your Sider.ini.