首先是删:
1 dbca删节点 rac1,按提示删除即可,其中需要输入sys密码
crsctl unpin css -n rac1
2#执行完grid用户查看资源池，此时rac2已经不在serverpool里，接下来继续删除cluster信息
srvctl config serverpool
cd /此处grid安装目录/bin
#停止故障节点集群
.\crsctl stop cluster -n rac1
#查看资源状态

crsctl status res -t
crsctl check cluster -all

#删除应用层

crsctl delete node -n rac1
crsctl stop resource ora.rac1.vip -f
crsctl delete resource ora.rac1.vip -f

如果vip还在,可以用如下命令删除vip
netsh interface ip delete address name="" addr=xx.xx.xx.xx
更新删除后信息：

cd -d %ORACLE_HOME%\oui\bin
.\setup -updateNodeList ORACLE_HOME=d:\app\11.2.0\grid  "CLUSTER_NODES={rac2}" CRS=TRUE
olsnodes -i -t -s

--执行删除后检查
cluvfy stage -post nodedel -n rac1 -verbose

增加节点

notepad C:\Windows\System32\drivers\etc\hosts
127.0.0.1       localhost
10.10.8.10  RAC-SCAN
10.10.8.11  RAC1
10.10.8.13  RAC2
10.10.8.12  RAC1-VIP
10.10.8.14  RAC2-VIP
192.168.1.11    RAC1-PRIV
192.168.1.12    RAC2-PRIV

#配置网络参数

netsh int ipv4 set global dhcpmediasense=disabled
netsh int ipv6 set global dhcpmediasense=disabled
netsh advfirewall set currentprofile state off
netsh int ipv4 set global dhcpmediasense=disabled
netsh int tcp set global chimney=disabled
netsh int tcp set global rss=disabled

#检查服务

net stop msdtc
net start RemoteRegistry

#添加节点

cd  -d %ORACLE_HOME%\oui\bin
set ignore_preaddnode_checks=Y
.\addnode.bat  "CLUSTER_NEW_NODES={rac1}" "CLUSTER_NEW_PRIVATE_NODE_NAMES={rac1-priv}" "CLUSTER_NEW_VIRTUAL_HOSTNAMES={RAC1-VIP}" 
D:\app\11.2.0\grid\crs\config\gridconfig.bat
set ROOTHASPL=%OH%\perl\bin\perl -I%OH%\perl\lib -I%OH%\crs\install %OH%\crs\install\roothas.pl -noterm
set ROOTCRSPL=%OH%\perl\bin\perl -I%OH%\perl\lib -I%OH%\crs\install %OH%\crs\install\rootcrs.pl -noterm

#添加后检查
cluvfy stage -post nodeadd -n rac1 -verbose
#添加db instance

set ORACLE_HOME=D:\app\Administrator\product\11.2.0\dbhome_1
cd %ORACLE_HOME%/oui/bin/
.\addnode.bat  "CLUSTER_NEW_NODES={rac1}"

参考:
添加crs:https://docs.oracle.com/cd/E11882_01/rac.112/e41959/adddelclusterware.htm#CWADD90997
添加db instance:https://docs.oracle.com/cd/E11882_01/rac.112/e41960/adddelwin.htm#RACAD8200