the model files from mosis will usually have the kp and kn values. if you dont have this information, then kn=Un*Cox ... Un is mobility of NMOS, Cox (Eo*Kox/Tox) is oxide capacitance, Eo is permitivitty of space, Kox is the dielectric constant, Tox is the oxide thickess. Be careful what units you use when you do the calculations. do same for kp.
lambda will have to be characterized. do an id-vd characterization and use the slope information for the device in the saturated region to estimate the lambda. the inverse of the intercept on the x-axis (vd axis) gives you lambda.