Database change – change templates for a specific custom post type

Hello,
I have several custom post types and I managed to work ok with your plugin – all custom post types have a field to select specific tempplate I made.
Now I have this situation:
– one of my custom post types (with many posts published) let’s name it “cptnm1”
needs a custom post template change

– all of them already have selected for example “cpt-template-1”

– it would be long if I have to click and edit all of them one by one to select different custom post template “cpt-template-2”

Is there a way I can run some function through database tables in phpMyAdmin to select all posts which are custom post type “cptnm1” and change their custom post type template?

Something like:

UPDATE wp_posts SET custom_post_template = ‘cpt-template-2.php’ WHERE post_type = ‘cptnm1’;

I have just a little bit of experience with database and phpMyAdmin, not enough to be sure what to do exactly.
I will make a backup of course – just wanted to check with you if this is possible and to check what is the right sintax for phpMayAdmin to make this change.

Thank you,
S