We are beginning siman 3. The Chayei Adam writes that it is a mitzvah for a person to be personally involved in the preparations for Shabbos. This is true even if a person has many servants, family members or other household help. We find that many amoraim undertook some action in the preparations for Shabbos, even though they were very busy learning and had others who could take care of the preparations.
The Chayei Adam points out that practically, it is important to help specifically in the winter months when there is concern that the house may not be ready on time and family members may come to violate Shabbos. Certainly, when it is getting close to Shabbos and one sees that the house is not ready, they must step in and work as diligently as possible to get everything done.The Chayei Adam writes that he has personally seen great men of tremendous stature who would step in and personally clean the house in the winter months in order to avoid any possible chilul Shabbos from family members.
There is no difference between one who has (Jewish) servants, who are unable to get all of the work done in time, and one who does not. Just as one who does not have any help, is responsible to get everything done, so too one ergo has help, but they can not finish in time. In regards to those chores, it is as if he has no people helping him. One cannot say that if they have hired help, it is the responsibility of the hired help to finish all of their responsibilities, because if there is not enough time, the hired help will end up violating Shabbos.
Regarding the idea that one must be personally involved in the preparations of Shabbos, the Chayei Adam writes that a person should not feel that it is beneath their dignity to perform such actions. In truth, by showing that one is willing to get dirty and work hard physically, one is showing true kavod for Shabbos. The Gra explains that, in the opinion of the Rambam (on Shulchan Aruch siman 529), kavod is all of the preparations done before Shabbos, and oneg is delighting on Shabbos itself. It is a kavod for Shabbos that we are preparing for it. We prepare for important events.
If so, the greater the stature of the individual, the greater kavod is displayed for Shabbos. The Chayei Adam is based on the language of the Rambam. Their point is not about getting the work done, but making a statement about the importance of Shabbos. By doing menial labor, this great person is making a statement that Shabbos is so important and that is why he would do work that normally is beneath his dignity.
One accomplishes this point by doing even one action. If one wishes to do more, it is praiseworthy, and if it is getting close to Shabbos, they have a responsibility to do more.
The mitzvah of kavod Shabbos is to be involved in the preparations for Shabbos, even if there are others who can perform the work. Certainly, if they need help to finish in time for Shabbos, one is responsible to help them.