If your ssd is just storing data and not the os (very likely) then you can setup the rpi5 as a new install on a new sd card. Then connect the ssd and mount the disk. This will not delete anything so long as you use ‘mount existing file system’ button.
You will need to reconfigure shares etc but this does not take too long (usually :-))
That's exactly what i want to do,i only use the SSD for storage and the sd card has the SSH connection and software,the problem i see whenever i try to mount it is i have to format everything and then it can be attached...