Stretch : mount Jessie encrypted HDD via USB

[commentsabout@riseup.net]

Hello,

I'm trying to connect my old Jessie HDD via USB in order to transfer
files to my new Stretch system (details below). It does not work out of
the box because it is encrypted, how should I proceed?

- I only have a laptop;

- 1 old HDD with Jessie (guided encrypted LVM install);

- 1 new SSD with Stretch (guided encrypted LVM install), this drive is
in the laptop;

- 1 S-ATA to USB adapter.

Needless to say that I have the passphrase for both systems. I am
actually worried to damage the Jessie system by using wrong commands so
I am looking for help.

Thank you in advance :)

CA