MIGRATION email clients to the portable Thunderbird application - please help!

As I please quickly, simply import all thunderbird content (all different accounts, data) into thunderbird portableapps as well as mail (originally stored or also from backup archive files) from other e-mail clients in OS windows 8.1pro 64bit...? I have the complete stored (cca 53GB) contents of directories, Thunderbird files in a portable USB HDD. Unfortunately, I don't get to the original Thunderbird profile, which was in the laptop because it's destroyed, so there was no backup total file created in that old app profile, nor did individual emails be stored in the files. Thank you very much in advance for your urgent help, clear instructions!