Problem migrating a sample project

Hello everyone,
On an attempt to learn doing games, i was working on an FPS project and tried to prototype it quickly in order to have a playable project quickly, so as to focus on the most important stuff.
In order to do so i downloaded the “Simple FPS Template” from Tom Looman. I adapted all the code to my project name, and migrated all his assets, but i had an issue. Everything migrated fine but two files did not: BP_Player and BP_Projectile, located in /game/blueprints/

From my very novice understanding of game-making and Unreal Engine, it seems like the parent class got lost since the old blueprints were targeted at “FPSCharacter” configuration.
If i open the migrated blueprints, i cannot even reparent them to “MyProjectCharacter”.

Now here is my question, is there a way to get out of this tricky situation without having to re-do the blueprints? and if the answer is no, is there (an actually good) tutorial for it, that does not involve fiddling around with blueprints “programming” like absolutely everyone does?

Thanks for your time,