Changing material properties between two steps with abaqus

[stbab]

I´m calculating (I started calculating) slope stability with abaqus.
Is it possible with Abaqus to change the material properties between two steps? I would like to calculate first the stress distribution (elastic) and add later with the load also the platic properties of the soil. I figured out, that for example the vicous properties can be suppressed by doing a static analysis and added in the second step by doing a vicous analysis.
Thanks