Lenovo Thinkpad E550 SSD and Memory Upgrade - YouTube
Lenovo Thinkpad L14 Gen 1 M.2 ssd upgrade | Lenovo Thinkpad L14 Gen 1 upgrade option | @lenovoindia - YouTube
BEWARE: Lenovo Thinkpad L15 Gen3 SSD is practically un-upgradeable. Laptop comes with 256GB and bigger SSD is too thick to fit. There also goes a cooling plate on top. : r/thinkpad