Firstly you need Adobe Lightroom (I use Adobe Lightroom Classic CC 2018) to be installed on your device. You can find it on adobe.com. Be sure to unzip downloaded Presets archives before installation.
Then there are two ways to install the presets:
1. The fast one:
a. Go to ‘Develop’ module.
b. Open context menu (by right-clicking or command+control-clicking) within ‘Presets’ section.
c. Click on ‘Import…’.
d. Locate and import the presets.
2. The ‘proper’ one:
a. For Mac: ’Lightroom’>‘Preferences’. For Windows: ‘Edit’ >’Preferences’.
b. Then: >’Presets’>’Show Lightroom Presets Folder…’>’Lightroom’ folder>’Develop Presets’ folder.
c. Copy and paste the presets to ’Develop Presets’ folder.
Applying the Presets is very easy, actually it’s oneclick action: after choosing the picture you go to edit in ‘Develop’ module and just click on the preset you want to use within the ‘Presets’ section.