As I know from old times water steam works nice.

Thanks, but that's old times. With the self-adhering stamps it does not work.

Dear Alisa:

Thank you for posting your question. Because for a long time - this problem was important for me too. I was sure that it has a simple solution - as  many times while in Japan - I saw that the labels glued/pasted onto a gift wrappings (with price on it) - was easily removed by some solvent by a shop-keeper if asked to.  However I  was almost absolutely sure that this trick - for stamps will be harmful. 

Yet a even for self-adhering stamps the solution does exist and it happens to be very simple - see the description in the file attached.

Best Regards,                              Leonid

Thank you so much Leonid

I will try it and share the results