Yeah you can replace the diodes. Just get the ones what are marked with the same Input power. I have a 12V 3A one with a 20W 450nm output.
You should see in the specifications what is the lasers input. The output can be different and do not need to be 1 to 1, as long the driver board can support what it needs, but ofc safer is to get the closest one to the original.
From where to buy it all depends, my own laser is ordered straight from China (Aliexpress) few years ago.

Hello.
People call me Suty, i am a self learning tech fan, have been fixing things here and there randomly sense i was 12.
First thing what i was able to repair was a older LCD TV what had a swollen capacitor in the Power supply and that trust in my mother towards me saved them buying a new TV for the next 10 years (Father was not happy LOL).
Now 17 years later i still have that bug to at least try and fix things.
I joined this Forum, because i randomly saw it and i always have been interested to learn and educate myself in that field.
Even tho i have had this little...