you can sync them while the system is in preloader. just use the red button on the wii by the SD slot and press the red button on the wii remote under the battery cover. Also read a use manual before F***ing with your friends stuff.
ok as for a way that works does the system have IOS 254 installed? check by scrolling through the possible boot IOS's for system menu in preloader settings. if it does set that to the system menu IOS and try to boot system menu. it should instead boot bootmii if you have the bootmii files on the SD card. from here you can simply find the precompiled version of Cboot2 or compile your own and use that to reinstall the latest system menu and an unpatched version of an IOS for use with the hackmii installer.
ok as for a way that works does the system have IOS 254 installed? check by scrolling through the possible boot IOS's for system menu in preloader settings. if it does set that to the system menu IOS and try to boot system menu. it should instead boot bootmii if you have the bootmii files on the SD card. from here you can simply find the precompiled version of Cboot2 or compile your own and use that to reinstall the latest system menu and an unpatched version of an IOS for use with the hackmii installer.