To vote an asset, follow the below mentioned steps:

Step 1:

If the asset is helpful, click on like icon button (highlighted in the below image) and gradually the count of the vote will increase which will also increase in the relevancy score for the asset.

Step 2:

If not helpful, you can click on dislike icon button as (highlighted in the below image) and gradually the count of vote will decrease which also decreases the relevancy score of the asset.