I put some eyelets into the poi cover, and tied the strings. This was quite ok (just required some strength as I inserted the eyelets with quite short pliers).
The eyelets in the poi were worse; I bought 6mm eyelets and tried to hammer them with a 7mm form, which was quite disappointing:-) I had to rip them out and repair. Fortunately, no consequences.
I had to send them soon (Christmas) so had to take photos even in a light rain.
All the flag poi are wonderful to spin with! I fell in love:-)