You can easily change the name of any track in your collection:

• Go to the «Music» section;
• Open the «My music» tab in the menu on the left;
• Open the collection with the desired track;
• Select «Edit» under the profile picture of the collection;
• Move your mouse over the desired track, click the three dots at the end of a line and select «Edit»;
• Enter a new name (you can also change artist and album names here);
• Click «Save»;
• When all desired tracks in the collection are renamed, click «Done» under the album cover.

See? It's easy!