Remove the miniature rose plant from its pot. Tap the sides of the pot gently to loosen the root ball from the pot, if necessary.
Clear old potting soil away from the root ball. Root-prune the plant by trimming long or compacted roots with sharp pruners or kitchen shears. Also trim off mushy or dead roots. Dispose of them with the old potting soil.
Fill a sanitized container part way with fresh potting soil. The diameter of the new container should be at least two inches larger than the previous pot. Mound the soil in the center, and place the miniature rose plant over the mound, spreading its roots around the mound. Continue filling the new container with soil, firming it around the roots with each addition to avoid air pockets. Plant the rose so the soil line on the plant is the same as it was in the old pot.
Prune dead or damaged top growth and dispose of it.
Water the miniature rose carefully to avoid splashing water onto the top growth.