Go here for Marc Carlson's drawings of these garments.
Go here for Maura Folsom's drawings of these garments.
Leonore's saya and pellote

Close inspection at the museum shows that there is a "tape" attached to the underside of the opening.
This is fastened down at regular intervals, and through this the laces are threaded.

Fernando's pellote

Cofia of Fernando, infante de Castilla