I hope I understand the question correctly .
When you move a post , the meta keys and values associated with it should remain with the post itself, like all post meta (including the attachments , custom-image etc..) – so there should be no problem to keep the values.
Normally ,The only thing that SHOULD happen is a change the ‘post_type’ property of the post.
but anyhow, if your question is about RENAMING meta keys , then this should dod the trick :
update wp_postmeta
set meta_key = 'new_key_name'
where meta_key = 'old_key_name'
Of course, to update VALUES you can use the same approach
UPDATE `wp_postmeta` SET `meta_value` = replace(meta_value, 'old_value', 'new_value') WHERE `meta_key` LIKE 'your_key'
EDIT 1 : i forgot to mention : ** BACKUP YOUR DATABASE BEFORE ANY TRIAL **
EDIT 2 : following comment :
To copy from one field to another (I got a bit confused with your naming and which value you want where , so I post the generic sentence.
UPDATE `TABLE` SET `FIELD2` = `FIELD1'