Hi Lubor,
Thank you for your purchase.

Words can be changed using POEDIT or Loco Translate for example very easily. I suggest you to install Loco Translate and then to translate these string.

If you want to use POEDIT then this is an instruction:

1. Download the Amelia plugin from our TMS Store or from email that you receive when you purchase our plugin and save the .zip file on your computer.

2. Unzip downloaded .zip file.

3. You need to download and install POEDIT. 

4. After that open the program and open the file from the extracted folder on your computer ameliabooking/languages/en_US/wpamelia-en_US.po.

5. Translate all the strings on your language.

6. Save the file as it suggests to you (the language code; for example wpamelia-id_ID.po if your language is Indonesian) and it will be generated new  wpamelia-id_ID.mo file. Find your language code here. 

7. Go to ameliabooking/languages/ folder and make new folder and call him as language code for your language (in our case for Indonesian is id_ID) and  then copy these two files called wpamelia-id_ID.po and wpamelia-id_ID.mo and then copy hole folder id_ID back to your website in the location ../wp-content/plugins/ameliabooking/languages/.

Of course, you will use language code for your language (we use Indonesian language and his language code is  id_ID just as example)

When you finish that it would be nice to send us that translation, so we can include in next major update so you don't have to copy this folder from local machine on every update.

Hope this helps If you have any more questions, don't hesitate to ask.

Best regards.