In DOSBox, hitting Ctrl+F5 stores a .PNG screenshot in a directory called "capture" (inside your DOSBox directory) with the name of the application, followed by a number (i.e. custlemm_001.png).
If you're not running DOSBox, you may be able to get a screenshot with "Print Screen", pasting it into Paint or related program.
Since you can only get one screen at a time, you'll have to take several screenshots (perhaps around 7 for that level) and link them together where they overlap. I usually determine where to overlap screenshots based on where there are non-uniform (non-black) pixels at the very top or bottom of the screen, because it makes linking the screenshots accurately very easy.
One thing you will want to do is edit in Attributes the height of each screenshot, so that it is 160 pixels, instead of 200. This is how you can discard the tool, etc. information at the bottom of the screen. Widen the size of the picture as you link them, up to a maximum of 1584x160 (I believe Level 8 requires this maximum size). I usually start linking from right to left, because it works more naturally in Paint, but find whatever way you want to link them.
And of course, pause the game, so that your screenshots look correct together. I pause the game before the windows are opened and try to get it so that in levels with traps, they can be clearly seen, like the fire-shooting trap in the Hell graphics set and the ice-shooting one in the Snow set. The same goes for thin one-way walls, where the arrows sometimes do not appear at all.
Here's the next level:
20041 - Level 2: Have a rotten day
&#A0; &#A0;
80 Lems &#A0;
75% to save &#A0;
RR: 1
Time: 5 minutes
Skills: 1 climb, 1 float, 3 block, 15 build, 3 bash, 1 dig
Good: Interesting reversal of entrance and exit, with of course some other modifications. It's possible (but perhaps too easy) to save 100%.
Bad: Seems easier than "Have a nice day!" The one-way walls really should be set to display on ground only. The one-way area on the steel block seems to serve no purpose.
