Yes it is.

Remove the black nylon end caps at the outer extremities of pedals. That will reveal the pedal's innerds, to access these innerds you will need to use a ratchet and the respective socket you need to loosen the retaining nut that is holding the pedal spindle in place along with its supporting bearings and races.

Assuming these cheapie loose-ball bearing pedals, it'll look like this inside:


Clean out the old grease and repack with new grease. In the process, look for damaged ball bearings and pitted bearing races. Pitted bearing races can be the deal breaker, if they are pitted, your pedal will feel rough/ course no matter what, repack or not. Replace damaged bearings with ones of same size; a moot point if the prior is true.