A multiple domain transfer is identical to the transfer of a single domain.
You can initiate the transfer of your domain to MyDataKnox here.

A domain transfer is actually a change of registry. It’s important to note that the transfer pertains only to the domain, not the hosting content. In other words, your domain can be registered with one provider, and the hosting (content) with another.

The duration of a domain transfer can be divided into two groups:

.hr i com.hr domains
The transfer of these domain extensions is the quickest. Prior to the transfer, the current registrar of the domain must unlock it for transfer, and an order for transfer must be placed with MyDataKnox. After the payment is complete, you’ll receive an e-mail containing a link for transfer confirmation. As soon as you click on the link in the e-mail and confirm the transfer, it should be executed in a matter of minutes.

.com, .net, .org, .biz, .info and other extensions
The transfer of these domains takes 5 to 7 days.
Prior to the transfer, the current registrar of the domain must unlock it for transfer and request an EPP authorization code which enables the transfer. After you’ve received the EPP code, you can place a domain transfer order with MyDataKnox. After the payment is complete, you’ll receive an e-mail containing a link for transfer confirmation. As soon as you click on the link in the e-mail, the process of transferring the domain from your previous registrar to MyDataKnox will start. It usually takes up to 7 days for the transfer to be completed.
If you want to transfer your domain to MyDataKnox, you can start the process here

A domain transfer starts with a domain transfer order on our website. Upon ordering a transfer, you’ll need an EPP authorization code for most extensions, which you can get from your existing registrar, and the domain must be unlocked for transfer. After you pay for the transfer, which is necessary since a domain is automatically prolonged for a year upon transfer, you’ll confirm the transfer by clicking on a link sent to you by e-mail. Afterwards, it’ll only take a couple of minutes up to a few days, depending on the registrar and the domain extension, until the transfer is complete.

The EPP key, also known as Authorization code, is one of the safeguards against unauthorized transfers of domain name registrations. The EPP key is required when transferring .com, .org, .net and various other domain names. You cannot initiate a domain name transfer for these domain extensions without an EPP code.

A domain transfer costs as much as the renewal of that domain.
When a domain is being transferred, it is also automatically renewed for another year, starting from the date of expiration of its current lease period. You can find the pricing of domain transfers here.

In order to perform a successful domain transfer, you have to meet the following requirements:

• You have be the owner of the domain or have access to the e-mail address indicated in the server as the e-mail of the administrator
• You need to unlock the domain for transfer with your current registrar and get an EPP code, which is required for most extensions (not for Croatian domains)
• The transfer must be initiated no later than 10 days prior to the expiration of the domain, so that it doesn’t expire during transfer
• The transfer must be performed at least 60 days after the domain has been registered or previously transferred.