chris is right, you maybe lucky and they accept your carnet. I travel without a carnet in South America.
I had parts send in from Germany twice.
Chile was a good place to get it send to by regular mail, a much lower bill worked and I only had to pay according to that for custom duties. But regular mail to Chile is very slow, best to receive it in Santiago.
Colombia I got parts with UPS. The value was declared at 25 Euros (25 USD), because they don´t accept any parcels without a value. UPS was fast, but not in Colombia. And I only had to pay 8 USD customs duties on the value.
Good luck MIKA