Does anyone know where I can hire a handyman in Saigon?

Without wanting to generalise, too much, I always get my locks from a person out of immediate area of the repair so that my information/home contents don't get 'broadcast' to local thieves.

When I buy a new key, I do the same AND NEVER GIVE MY ADDRESS.

The 'Euro' lock - very common now in VN - can easily be changed by even a rank amateur.

1. On the edge of the door there is a plate through which the 'bolts' emerge to engage with the frame. Remove the two screws and the cover plate.
2. Under the plate there is another screw (usually 2 or 3 mm) in the centre. Remove this.
3. The lock mechanism can now be pushed out.
4. Insert new mechanism.
5. Screw in centre screw and re-install cover plate.

'Flat' keyed locks are insecure, a flat piece of metal and a wire is all it takes to open them.

GERMAN MANUFACTURED locks are the most secure.

Electronic (card) locks are a joke! (But they do look impressive)

Glass windows can always be replaced with tough POLYCARBONATE (ask and I will give you supplier address).

Many windows in metal door frames are held in with a small frame the size of the glass secured with screws. Heat is often needed to loosen the paint around the screw. Use a soldering iron OR some round iron dowel (rod) heated up on a gas burner.

The biggest challenge is finding a skilled/qualified worker - so many local jobbers are just 'hackers' which is why Foreigners investing in construction projects import skilled workers.

SOFIA (OP): What part of HCM are you in?