Try multiplying the phasor you want to rotate with a gain block of gain such that and . This shifts the input phasor at the required angle without changing the magnitude. You could view the magnitude and phase of the output phasor using Complex to Magnitude-Angle block. Please refer the attached figure to see how these blocks are connected. Hope it works.
It is useful for my problem. Moreover, I find it is also valid by adding a phase shift in phaor angle captured by 'Fourier Block'. Thank you for your help.