Jeremy,
I like your solution, but (because I'm newby in integrity) I do not understand 100 percently the using on -F
I have already the needed query as you can see above.
> im issues --query=ID247485_HasValidates --fields="Validates" > relationships.txt
- How can I tell the editissue to which item in file wich issue belongs to?
- What if there are more then one relationship to the item, which relationships I want to delete
help of -F says:
provides an alternative way to specify the selection. The specified file is a text file containing a list of file names, members, projects, or
sandboxes, one per line. The command operates on all the listed files.
I think it cannot work in this case because of 'one per line' construction,
But you gave me a good idea; the solution 
I wrote a small bat file:
echo off
setlocal EnableDelayedExpansion
REM variables
set _myquery=ID247485_HasValidates
set _usr=jozsef.szlatki
set _logfile=RemovedRelationships.txt
echo All relationships are removed based on the query %_myquery% > %_logfile%
REM functions
set $get_relationships=im issues --user=%_usr% --query=%_myquery% --fields="ID,Validates" --fieldsDelim=;
REM get issuId and the relationship(s)
for /f "tokens=1,2 delims=;" %%A in ('!$get_relationships!') do (
set _dy_issueID=%%A
set _dy_relationships=%%B
REM remove issuId and the relationship(s)
im editissue --user=%_usr% --removerelationships="Validates:!_dy_relationships!" !_dy_issueID! 2>> %_logfile%
)
REM open the logfile, of course it could be pretty-printed
%_logfile%