Whilst in the container, place the rose in the hole and check that the crown of the plant is at ground level. The ‘crown’ is the base of the plant where the stem and roots meet. If the crown is not at ground level, remove/add some of the compost/soil mixture until it is.
Gently remove the rose from the container and carefully tease out some of the roots from the root ball before placing it into the centre of the hole. Teasing out the roots will encourage them to grow away from the plant into the surrounding soil.