Surfans F20 / Opening unit and upgrading/replacing battery?

[OutofStep]

I have the Surfans F20 and knock on wood, it's still working ok, but was taking a look at it and am trying to figure out on how to open it with the intention as to replacing the battery as well as to see if anyone here knows if there is a larger capacity battery that will work with the unit (for longer play time) than the default 1500mah one?

Can anyone let me know or point me to disassembly links?  I've tried googling but haven't turned anything up and don't see anything here.

[vitt13]

Can anyone let me know or point me to disassembly links?

Here is the video https://www.youtube.com/watch?v=k9pza1XTIU0

[lubatur]

Due to a bloating of the original battery with 1500 mAh (runtime at that time: 8 hours) after 1.5 years of use, I replaced it with one with 2000mAh.
Runtime with the new battery: 27 hours (!) playing mp3-files.
Time until the battery is fully charged: 4 hours.
The exchange was very easy after opening the player (see video above - by 2 soldering points) and the battery fits perfectly into the case.

Battery data:
"EREMIT LiPo Battery Lithium Polymer 2000mAh 3.7 V 1S Powerbank 634168 PCB 27"
Length: 68mm
Width: 41mm
Height: 6.3mm
Weight: 35g
Rated voltage: 3.7V
Capacity: at least 2000 mAh
Date of production in my case: Dec. 2022
Price including shipping: 14 €
Source of reference: https://www.amazon.de/dp/B07XDM4NDR

Question:
Is it possible to adjust the expected remaining runtime (visible under System > Rockbox Info)?
Here, only exactly 13 hours are displayed with a full charge. I think referring to a battery with 1300 mAh (according to: Plugins >  Applications > battery_bench).
The percentage is correct.