[SOLVED] Personalized printable copy of the order confirmation

It would be possible to adapt the order confirmation (Click here for a printable copy)?

I would like to adapt the shop to the sale of my services and do not need some fields.

Hello, depending on the version the files could be located in different folders. Just search for: printable_order_copy.inc.php and edit it.
There are more than one file with the same name.
I edited the one in \litecart\includes\templates\default.catalog\pages

Very thank vilaiporn for your advise! But I was hoping for a permanent customization solution; which will not be overwritten with the next product upgrades. 
I are in development on a new Litecart shop for my web services. My products are only online web and design works such as domain name sales, complete Website-Projects and the creation of new design websites.
As a permanent personalization, compatible with the future versions, I unfortunately only see the possibility of translating somehow these unnecessary fields.

Hello, you could write a note and keep a copy of the modified file, after the update you can redo it with a relative little effort. Yes, it is not automatic...

Of course; I always make copies of the original files and insert comment lines on the changed code. However, I am not alone in keeping our customers' sites up to date. Getting hands on these websites after months it becomes a problem to pick up notes for each individual customer and changes to files that are often scattered in the different cms structures.

Unfortunately a lot of this time is not recognized or paid by the customer while the updates are more and more.
Thank you for your advice and willingness!

@fritz
[quote]But I was hoping for a permanent customization solution[/quote]
This is exactly what vQmods are for.  You can write a mod that changes the files in question, and that mod will never be overwritten during the next upgrade.  It's the perfect solution to a lot of problems.

[url=https://wiki.litecart.net/how_to_create_a_vqmod]How to create a vQmod[/url]

Thank you s22_tech for your suggestion. However, that's not what I meant. I was thinking more of a module or a similar interface for the end user, something that an end user can manage directly.
Personally I have limited knowledge with the php language and, from what I read in GitHub, these scripts interface directly with the PHP core code. I will take a look to understand better but I fear these are advanced technical interventions that I should pass to the php script programmer.