The photographical reproduction of this work is covered under the article § 59 of the German copyright law, which states that "It shall be permissible to reproduce, by painting, drawing, photography or cinematography, works which are permanently located on public ways, streets or places and to distribute and publicly communicate such copies. For works of architecture, this provision shall be applicable only to the external appearance."
As with all other “limits of copyright by legally permitted uses”, no changes to the actual work are permitted under § 62 of the German copyright law (UrhG).
In case this is not legally possible: Januar255 grants anyone the right to use this work for any purpose, without any conditions, unless such conditions are required by law.