If the 1.3 is th OHV version which I reckon it is, you will have to change the engine mount. The gearbox from the 1.3 will bolt straight on but you might find it too low geared so you might be best swapping it for the matching 1.6's gearbox. Wiring in the EFi should be simple enough as long as you got all the engine loom with the EFi engine. The radiator will also have to be swapped as the entry and exits are different. Another consideration would be the brakes. The 1.6 EFi has about 96 BHP whereas yer 1.3 OHV has about 60 on a good day! Shouldn't be to expensive to get some S/H calipers and new discs and pads arent that expensive for the 1.6 Escy.
i reckon you'll find it cheaper to actually sell the car and buy a 1.6 escy as you will have to insure your 1.3L as a modified car, which aint gonna be cheap.