I forgot to press stop at end of hiking.

[Razvan Sandulescu]

How can I delete extra part of the recording?

[Jan Buriánek]

It’s not possible to directly edit recordings in Mapy.com.
However, you can do it via GPX export and import.

The process is to export the track, edit it in an external editor, and then import the edited version back into Mapy.com as an activity.
This way, you can shorten, extend, or fix gaps in the track.

Instructions on how to do this using the website gpxmapy.cz are available here. The site is also available in English.