No-one seem to have a diagram on the repeater but I did find this on the web.
see the link below
See the link below for reassembly.
go on the computer and scan the words 'marksman air pistol' ...............
See the attached Link: https://www.youtube.com/watch?v=H5qbEgnSZF0
which Model are you asking about
To get an answer you will have to state the condition of the pistol & is it still working?
Starting in 1977 to present
Marksman doesn't list the cocking effort but believe me it's very little. The pistol only fires a 220 FPS and that is slow.
200 Feet Per Second (FPS)
There's a double action to the slide - see the link below for a manual:
Marksman made several models. Which one are you asking about.,
somewhere around $30
marksman