Do you mean downshifting into 1st gear when still going 5-10mph, such as when slowing for a red light that just turned green before you came to a stop? You'll probably notice that it's pretty hard to go into 1st gear at speeds above 5mph, but if you're determined enough you can just force it as long as you have the clutch pushed in.
If you're looking for a more graceful way to slide back into 1st gear, you'll need to make use of the age-old method of double clutching. This consists of shifting to neutral, releasing the clutch, revving up to a little higher than the target RPM, then pushing the clutch back in and quickly going for 1st gear. If you do it right, it will slide right into 1st with nearly zero effort and when you get your foot back on the throttle and release the clutch you'll already be at target RPM.
If you're looking for a more graceful way to slide back into 1st gear, you'll need to make use of the age-old method of double clutching. This consists of shifting to neutral, releasing the clutch, revving up to a little higher than the target RPM, then pushing the clutch back in and quickly going for 1st gear. If you do it right, it will slide right into 1st with nearly zero effort and when you get your foot back on the throttle and release the clutch you'll already be at target RPM.