Ikonta 523/16 cleaning

Does anybody know how easy it is to remove the top on a Zeiss Ikon Ikonta
523/16?

I have the problem that after a picture is taken a little window should turn
from red to white.
This can take a while and before it happens it is not possible to release
the trigger to take
another picture. So I want to clean it. For doing that I need to remove the
top I assume?

The camera has a coated Tessar 75/3.5. Shutter is a Synchro Compur which is
a little slow
on 1 sec. I have never seen what a Zeiss Tessar can do. I want to know if it
is waste of
time and money to have the shutter cleaned. Maybe it is just a collectors
item. Time will
show......I hope.

It is not an Opton Tessar. Some claims that they are a lot better. My is not
branded Jena
either....just Carl Zeiss Tessar. Some of the black painting get off very
easy......is that common?
I have nearly removed the all....which makes the camera look better.

Max