Huge challenge is figuring out the LCD pinout.
Having the knowlege that a DTM0660 chip is used, the pinout of the back-connector can be determined.
That was the easy part. Following is to find out, which combination is connected to which segment...
The LCD screen can be seen as an array. By selecting a COM (common) output and SEG (segment), a specific segment will become black. Of course, driving the segment, should be done with an AC signal so that 0V DC offset is reached. More on that principle can be found in this video of Dave Jones (EEVBlog) https://www.youtube.com/watch?v=mo4_5vG8bbU