[split] Change password from external media

[James Good]

>onto a micro USB,,, surely you mean micro SD? (uSD)
Is there still a bootable distro on the emmc?  If so, edit password file, /mount-point/etc/shadow (ON EMMC)
You can edit a user password too, if needed
As to wifi, check with ifconfig  OR  ip a  (all this as root or sudo)
because of systemd, the normal command may not work, refuses (wifi) password
nmcli dev wifi con <ap name>  -a    (-a=--ask)
What I had to do (in vt - virtual terminal)
nmcli con up <ap name> -a
If unsure of name,,, nmcli dev wifi list

wdt,
You are right, the card was misidentified by me.  It is a microSDHC card.  As for an earlier distro on the emmc, I am not sure.  In truth, I am almost a rank amateur when it comes to almost anything Linux.  And my knowledge of the inner workings of any other computer language is about the same.  I will keep your suggestions and work with them on the laptop.
Thank you.
James Good

[wdt]

I'll try to make it simple, assuming a SD boot with manjaro
lsblk -a ,,, your SD is /, probably mmcblk1p2 ,, ie blk1
Probably emmc is blk2, root filesystem on that /dev/mmcblk2p2
It will be more easy since SD card is 32G and emmc is 64G, so size makes it clear
Start filemanager dolphin, left column click emmc drive (note size to be sure)
If there is a still a distro installed, the regular directories will be there,
bin, boot, home, etc, opt , root, sbin, usr and so on
click etc (to change to that directory), press f4 to get command window, resize larger
double check
df -h (is emmc mounted? size shows)
pwd (where am I? /mountpoint/something/etc/)
sudo cp shadow shadow.bak
sudo nano shadow
Do editing mentioned 3 posts above
Shutdown, remove SD card, reboot