Correct it, please!

[sweetie_sneha]

Hi,

How to correct the following letter?

This is to request you to kindly issue all cheques from now onwards in the name of HarshaTrading Est. which is our sister company instead of Royal Trading Est. The following are the bank details:

..................................
.....................
.............................

for Royal Trading Est.

[fallingstar]

here by i (through this letter i would like to) request you to kindly issue all cheques, now onwards in the name of Harsha Trading EST, instead of roy at trading est. Harsha Trading Est (it) is our sister company.

i don't how much it is correct, it is like one blind guiding other blind...

[Tdol]

I'd just add a comma before 'instead'