How do I properly tell someone to proceed with a transaction in an email?


Today, I received the following email after an online purchase:

> この度はご注文いただき誠にありがとうございます。
>
> 頂きましたご注文の発送方法について、EMS(国際スピード郵便)による配送となりますので、 送料が1,500円かかります。
>
> よろしければ、クレジット決済金額の変更をし、商品を発送いたします。 お手数をおかけいたしますが、ご返信をお願いいたします。

I am having a great deal of trouble finding common phrases to respond to in
e-commerce related conversations over email.

What is the proper way to give the sender permission to proceed?

Every phrase that I would like to use in English seems to have a dual meaning
which does not work in Japanese (e.g. please go ahead), or produces very few
google results for the phrase which suggests to me that no-one speaks in that
manner.

I spent several hours trying to find a way of saying, "Is it possible to use
registered shipping instead? If not, please proceed."

My best attempt is something along the lines of

「書留郵便ができるでしょうか？如何とも決済金額の変更して, 追加送料を払ってください。」

but I really have no idea how accurate my vocabulary is. Considering some of
these words yield little to no search results when I google them, I suspect
this is wrong.

Where can I even find examples of conversations of this nature to learn what
to say?




> Is it possible to use registered shipping instead? If not, please proceed.  
>
> EMS(国際スピード郵便)ではなく、[国際書留](http://www.post.japanpost.jp/int/service/option/registered_merit.html)で送っていただくことはできませんか。もし無理なようでしたら、そのまま(1,500円のEMSで)手続きを進めてくださって結構です。

![](https://i.stack.imgur.com/HPF8d.png)

