its very easy on a mehran. when you remove sump make sure it is perfectly flat too - find a perfectly flat surface and check it, you may find its warped out of shape - in which case you will need to hammer it straight again. If the sump is not sitting flat, it will leak.
What gasketing are you going to use? a cork/paper gasket or FIPG sealant tube?
when installing the sump ensure that all threaded holes are clean and your bolts are clean and you have all of them. first install them one or two threads only that way you can install all of them and then tighten them - they are very gently tightened (approx 80 in/lb) - this is screwdriver tight only, do not go crazy on tightening the bolts. They are tightened in a criss cross sequence or circular sequence ideally in 2 steps.
I also always used to install two "guides" to install any sump - I used grub screws of the same threading - you can buy two longer bolts and cut their heads - this small addition provides easy alignment so that the sump goes on perfectly straight to the block without trying to guess where its going. Once all other bolts are in - remove the guides and install the correct bolts back.