1st variant

1. Right click on the file
2. Open with
3. Select another app
4. Select the software you want> Always use this app to open files

2nd variant

1. In Windows Settings, select the App and Standard Apps category.
2. Decide which app you want to use as the default and select it. You can also get new apps from the Microsoft Store. Apps must be installed before they can be set as default 
3. You may want to automatically open PDF files, emails, or music using applications other than those provided by Microsoft. To select the default application by file type , scroll down and select Select default apps by file type .
4. Here you can search for your desired extension (.pdf, .png, .docx) and define the desired program as the standard.