Safe/recommended way to disconnect BMS (at the bus bar side)

[mbp566]

I own a 48V 200Ah battery that stopped working recently (it does not start at all).
Specifically, it is a Rosen battery and it uses a Seplos BMS.
I bought this is 2021 and after few searches here and on other websites I quickly found out that BMS produced by Seplos at that time have a defective diode.
Since it's just one component, I will try to change it myself (there's no way Rosen or Seplos will service this anyway, I'm not even trying to ask them)

I have good soldering skills so I'm not concerned about that, but I need to disconnect the BMS and remove it from the battery temporarily to change the diode (and reconnect it afterwards)
I found a replacement guide (I can't attach the whole thing because it's too large, so I took a screenshot of the relevant part).
The English is pretty bad...from what I can understand the steps are:
- Remove the battery +
- Remove the two harness (I assume those are the 2 connectors with sensor/leads)
- Remove the battery -
It does make sense to me but as I've never done this I'd like to know if any of you here have a different opinion.
Also in general, I would really appreciate any advice as to what do/not do/be careful of (I've already checked online quite a lot)

Finally I have another question: Is it ok to disconnect the battery (especially the + side) at the bus bar (not the BMS side) ?
I'm asking because the + side of the battery has a single bolt on the bus bar where 3 wires are connected, and 1 bolt for each of those wires at the BMS side.
I'm fine with unbolting 3 bolts, but, given the location of the BMS it seems super easy to make a short while removing bolts (the 3 wires will be hanging in the air after disconnection, but still be active, and the battery is almost full right now at 50.7V).
PS: I can attach a picture if needed.

 

[stromy]

First, to do this safely, you need proper isolated tools and isolation accessories. In addition you need ESD protection.
- shut down the battery/BMS, switch it off, disconnect from busbar/inverter. If needed isolate energy wires with isolation caps.
- open the case of the battery, make sure to not drop anything in.
- remove one of the connections between the cells. So even if you accidentally touch something no current will flow.
- Cover the cells with an isolation sheet.
- disconnect the battery-BMS energy connections at the BMS side. Cover the cables with isolation caps.
- disconnect the battery-BMS sense connections, signal connections, user connections, etc. Make a photo first, if there is no protection against wrong assembly.
- remove the BMS
- remove the buffer coin cell battery from the BMS.
- do your repair
- test the repair. A short will definitely ruin your day!
- assemble everything in reverse order.
- switch on according to the procedure of your inverter or battery docs. E.g. if there is no inrush current limit, you man need a power resistor or light bulb to equalize the voltage.

 

[~Yuri~]

I also had to change the diode D4. Engineer Seplos sent me the manual. I'll try to post it here.