It is known to us that Syria was under French occupation from 1920 to 1946, and as a result of that, some French firearms from that era were left when they evacuated. Ayham is a Syrian cartoonist – he draws political caricatures and educational ones for kids on his YouTube channel. This was the only firearms-related video on his channel where he shows how he modernized a French-made MAS-36 rifle which he realized wasn’t pleasant enough for him and impractical with its 5 rounds magazine and classic stock.
Syrian Guns @ TFB:
The first thing was when he realized that the wooden handguard was heavy and prevented barrel cooling so he decided to drill some holes for ventilation and as a cosmetic feature.

Note the vent holes drilled in the handguard
Second, he hollowed the buttstock and fixed a specially designed part to it to give him a better grip on the rifle and to reduce some of its weight. The changes make it look sort of like an SVD buttstock.

The buttstock after being hollowed and ready for the customized part with a pistol grip to be attached (Also note weld marks on the magazine prior to the paint job)

Lower wooden rib and pistol grip attached
The third modification to this MAS-36 was the most important one, the conversion of 5 round fixed magazine into a 15 round detachable box magazine by using some parts of the old one. Let’s see how did it.
Step 1: Removing the fixed magazine and getting rid of the lower magazine’s plate except for the release button which he later cut then weld to the new detachable magazine.

An arrow pointing to the magazine catch/release button regarding its importance in the new magazine built
Step 2: Getting rid of the magazine leaf spring since it’s short and can only feed 5 rounds, then replacing it with a spring similar to a 7.62x51mm magazine. The follower was kept because he wouldn’t be able to find a similar one for such an obsolete rifle.

Magazine follower is to be re-used in his description
Step 3: The new magazine itself was nothing but a metal sheet bent to the shape and size of the old magazine but extended. I don’t know why he loads from the receiver top while the magazine is attached, therefore I have no idea whether he made magazine lips or not.

Close-up view on the modified magazine
In the end, these modifications were not so hard to make yet still creative and the ammunition feeding and ejection seems to work pretty well.
Here is Ayham’s video of his MAS-36 modifications.