93glexplorer

I need help. I bought my 93 explorer last march as a bargain deal at a local dealership. i was changing spark plugs today and the oil and I noticed a few cracks in my radiator cooling fan. some cracks are deeper and larger than others. is it crucial that i replace the fan as soon as possible or can i wait till spring. Also, I want to replace it myself to avoid high labor fees. how difficult is it to replace the fan myself?

thanks for your help!