You can use a differential amplifier to add an offset to the signal.
View attachment 71115
Use an Rf value lower that R1 to attenuate the input and apply an offset to Vr , for example R1=10K and Rf=5K attenuates the input by half so -5 to +5 becomes -2.5v to +2.5v .
Now if you apply 2.5v to Vr then you get an output of 0 to 5v.
If you don't have a supply more than 5v for the opamp then you should use a rail to rail model that is able to give 5v output or you can attenuate the input more to get 0-4v (and a 2v offset)